Sixth-grader Lipine Faafiu found a comfortable perch to view the coral reef tank. Over 600 students from low-income area schools attended a public science day at the California Academy of Sciences in San Francisco, Calif. on Wednesday, February 14, 2007. The day-long event coincided with the annual conference of the American Association for the Advancement of Science which is convening in San Francisco this week.
PAUL CHINN/The Chronicle
**Lipine Faafiu

Photo: PAUL CHINN

Sixth-grader Lipine Faafiu found a comfortable perch to view the...

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Rodnique Whitley (left) and Jacqueline Nguyen, from Visitacion Valley Middle School, seemed amazed by fish swimming in the tanks. Over 600 students from low-income area schools attended a public science day at the California Academy of Sciences in San Francisco, Calif. on Wednesday, February 14, 2007. The day-long event coincided with the annual conference of the American Association for the Advancement of Science which is convening in San Francisco this week.
PAUL CHINN/The Chronicle
**Rodnique Whitley, Jacqueline Nguyen

Photo: PAUL CHINN

Rodnique Whitley (left) and Jacqueline Nguyen, from Visitacion...

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Peter Suen, a 7th-grader from Visitacion Valley Middle School, listens to a presentation about alligators. Over 600 students from low-income area schools attended a public science day at the California Academy of Sciences in San Francisco, Calif. on Wednesday, February 14, 2007. The day-long event coincided with the annual conference of the American Association for the Advancement of Science which is convening in San Francisco this week.
PAUL CHINN/The Chronicle
**Peter Suen

Photo: PAUL CHINN

Peter Suen, a 7th-grader from Visitacion Valley Middle School,...

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A baby American alligator was among some of the animals displayed for over 600 students from low-income area schools that attended a public science day at the California Academy of Sciences in San Francisco, Calif. on Wednesday, February 14, 2007. The day-long event coincided with the annual conference of the American Association for the Advancement of Science which is convening in San Francisco this week.
PAUL CHINN/The Chronicle

A smorgasbord of science is on the menu in San Francisco this week as members of the world's largest scientific organization gather to report their research progress, ponder global policy and hear the famous explore the future in every field from anthropology and astronomy to zygotes and zoology.

It's the annual meeting of the American Association for the Advancement of Science, and starting today, thousands of researchers and policymakers from 60 countries will hear 800 of their colleagues report on progress in advancing knowledge at 200 separate symposia and plenary lectures.

Above all, leaders of the science community will weigh the most urgent world problem now linking science and public policy -- the impact of global warming. They will also hear reports on topics that include the future of basic research; government budgets for space, health, energy and pollution; and all the other issues confronting the scientific community.

But not all the science will be arcane. Bay Area residents of all ages will find plenty to choose from Saturday and Sunday in a festival of scientific wonders. Those events are free to the public.

The big gathering starts today at the Hilton and Nikko hotels.

The meeting's theme is "Science and Technology for Sustainable Well-Being." John Holdren, the association's president, said Wednesday that the greatest threat to the Earth's well-being is increasingly rapid global climate change.

The evidence for dangerously climbing temperatures is "absolutely stunning," Holdren said in a discussion with The Chronicle's editorial board. He cited such phenomena as the damage now caused worldwide by floods and wildfires, the spread of malaria in the tropics where mosquito populations are increasing, and the rapid melting of permafrost in the Arctic tundra as well as the swiftly increasing loss of ice in both polar regions of the globe.

He noted that virtually all climate scientists agree that global temperatures are rising, and that the major cause is increased greenhouse gases -- largely from the burning of fossil fuels.

The world's most urgent need, he said, is "a massive effort to slow the pace of global climatic disruption before intolerable consequences become inevitable."

The scientific community can certainly help develop new technologies to cope with the problems, he said, but with the pace of climate change increasing so rapidly, "we've only got about a decade to get things right."

On Sunday, he will preside over a public town-hall meeting on climate change, tailored to teachers, students, policymakers and the general public. It will start at 1:15 p.m. in the Hilton's Continental Ballroom. Leading experts will discuss the evidence and offer steps both individuals and governments can take to help solve the problem.

These efforts, Holdren said, can be as straightforward as individuals shifting to hybrid cars and fluorescent lightbulbs or governments and industry curbing industrial carbon emissions with carbon taxes or carbon-trading incentives.

Scientists will be considering all these issues during the meeting this week, but many of their sessions will deal with a range of other research topics. They'll discuss controversies over teaching evolution; the habitability of Mars and other planets; technologies to provide clean water and nutrition for the developing world; nuclear weapons and nuclear power; and much more.

On Monday at 8 a.m., also at the Hilton, atmospheric scientist Susan Solomon will give the final public lecture. Solomon, a leader in drafting the most recent United Nations report by the International Panel on Climate Change, will discuss the major elements of the document in detail.

The American Association for the Advancement of Science, together with Bay Area museums, universities and other organizations, will host two "Family Science Days" at the Hilton on Saturday and Sunday from 11 a.m. to 5 p.m. Events will include laboratory demonstrations, stage shows, lessons on making robots, yo-yo science and other hands-on activities, and interactive experiments from San Francisco's Exploratorium.